Respuesta :
Answer:
The boat traveling at 24 kph when John goes downstream.
Step-by-step explanation:
We are given the following in the question:
John has a boat that will travel at the rate of 15 kph in still water.
Let x be the speed of the current.
Speed of boat in upstream
[tex](15-x)\text{ kph}[/tex]
Speed of water in downstream
[tex](15+x)\text{ kph}[/tex]
Relation:
[tex]\text{Speed} = \dfrac{\text{Distance}}{\text{Time}}[/tex]
We have to find the speed of boat in downstream.
Time to travel upstream for 35 km = Time to travel 140 km downstream
[tex]\displaystyle\frac{35}{15-x}=\frac{140}{15+x}\\\\35(15+x) = 140(15-x)\\525 + 35x = 2100 - 140x\\175x = 1575\\x = 9[/tex]
Thus, speed of current is 9 kph.
Speed of boat in downstream = 15 + 9 = 24 kph.
Thus, the boat traveling at 24 kph when John goes downstream.
